Until now, the formation of a process line from a plurality of process devices has been conventional within the scope of spectacle lens production, the spectacle lens blanks to be processed passing therethrough in succession. Then, the process line is set, for example, to a certain sequence of process steps and a certain surface design and certain finishing of the spectacle lenses.
Usually, all process devices and transport devices, which transport the spectacle lens blanks to the respective process devices of the process line, are controlled by a central controller. In particular, which process device processes which spectacle lens blank in what manner is set centrally, for example.
Use of a multiplicity of transport devices for transporting the spectacle lens blanks to the respective process devices is known from the related art.
By way of example, there are link chain conveyor belts as described in WO 03/013992 A1. There are also rail systems of the type described in DE 195 06 670 A1. Further, roller conveyor systems exist, as are disclosed in EP 1 947 035 A1, for example. Finally, conveyor belts or belt conveyors are also known. An exemplary embodiment of a conveyor belt or belt conveyor can be gathered from DE 20 2012 011 690 U1, for example.
In general, not all process devices of a process line are strung in succession on a transport track formed by one or more transport devices; instead, at least some of these process devices are situated next to the transport track. Moreover, there regularly is not just one transport track but a plurality of transport tracks next to one another. Finally, there are also crossing or branching transport tracks. Firstly, this requires the option of transferring the spectacle lens blanks from the transport track on which they are transported to the respective process device in which they should be processed further and, secondly, this requires the option of transferring the spectacle lens blanks from one transport track to an adjacent transport track or from a currently transporting transport track to a transport track crossing or branching off the latter. Appropriate transfer devices adopt this object.
The related art discloses a multiplicity of transfer devices. A selection of these will be presented below.
DE 20 2012 011 690 U1 and WO 2013/131656 A2 each describe installations for producing spectacle lenses. The corresponding installations comprise a plurality of separate processing devices and belt conveyors or conveyor belts for transporting the spectacle lens blanks to be processed to and from the processing devices. The installation comprises a plurality of transport tracks, which are formed by belt conveyors or conveyor belts, and transfer devices crossing the transport tracks at right angles, the transfer devices likewise being formed by belt conveyors or conveyor belts. The belt conveyors or conveyor belts forming the transfer device, which are arranged transversely to the transport tracks, are raiseable and lowerable. By raising or lowering, the transport containers for belts transporting spectacle lens blanks, of the belt conveyors or conveyor belts of the transfer device can be brought into a plane lying either above or below the plane of the belts, provided to transport the transport containers, of the belt conveyors or conveyor belts of the transport tracks. If the belts of the belt conveyors or conveyor belts of the transfer device are in the raised state, the transport container only lies on the belts of the belt conveyors or conveyor belts of the transfer device and a transfer of the corresponding transport container onto an adjacent, branching or crossing transport track or to a process device is possible. If the belts of the belt conveyors or conveyor belts of the transfer device are in the lowered state, the transport container only lies on the belts of the belt conveyors or conveyor belts of the transport track and transport along this transport track is possible.
A similar transport and transfer system, albeit based on driven rollers instead of the belt conveyors or conveyor belts, can be gathered from WO 2008/006644 A1.
The link chain conveyor belts according to WO 03/013992 A1 are equipped with switches, which likewise operate on the principle of raising and lowering.
DE 10 2007 059 303 A1 discloses an installation with a main conveyor belt, which has at least two tracks circulating in the same direction. An outer track serves as an overtaking track, on which workpieces or workpiece carriers that should not be supplied to processing are transported onward. A change from one transport track to another transport track is implemented by sliders and associated stamps. Moreover, transverse conveyors with conveyor belts running in the opposite direction are assigned to each processing station, wherein workpieces or workpiece carriers to be processed are offloaded by means of corresponding switches from the main conveyor belt to the transverse conveyors for the purposes of processing in the respective processing station.
EP 1 947 035 A1, from which the disclosure proceeds, describes a roller system. A transport track is formed by a multiplicity of rollers, which are arranged in succession with their axes transverse to the transport direction. A transport container lies on a plurality of these rollers that form the transport track. One or more of these rollers are driven by a motor-type drive; in one described and sketched exemplary embodiment, a transfer device is formed from twenty short rollers, which are arranged in matrix-like fashion and which form the crossing of two crossing transport tracks. Five short rollers in each case span approximately the length of the rollers forming the transport track.
Each short roller is a constituent part of a cell. Each cell comprises a dedicated drive for driving the roller about its roller axis (i.e., its cylinder axis). Further, the cell comprises an additional dedicated drive for rotating the roller about a central axis extending perpendicular to its roller axis. The transport direction and alignment of a transport container lying on a plurality of the short rollers can be set or changed by an appropriate choice and change in the rotational speed of the respective roller about its roller axis and a corresponding choice and change in the alignment of the roller axis by rotation about the central axis.
US 2003/0161714 A1 describes a storage and buffer system for transport containers that are used in semiconductor manufacturing. The system comprises rotation means in order to transfer the transport container from the conveyor belt into the storage and buffer system, or vice versa.
EP 3 064 455 A1 discloses a conveyor device with one or more rotatable conveyor means.
A conveyor device with a grid-like structure for transporting transport containers between process stations can be gathered from US 2009/0099686 A1. A rotary conveyor means is arranged at each grid point. The transport to each rotary conveyor means is implemented by means of non-rotatable linear conveyor means. Such a conveyor device with a grid-like structure is also described in U.S. Pat. No. 6,425,477 B1.
Rotatable roller conveyor means, inter alia, are gathered from US 2013/0192954 A1.
WO 2015/173689 A1 relates to a conveyor system for conveying containers. Linear and rotary conveyor means are constituent parts of the conveyor system.
JP2009137687A discloses rotation/transport devices arranged in matrix-like fashion. A transport container is borne simultaneously on the bearing surfaces of a plurality of rotation/transport devices of the rotation/transport device matrix. Adjacent rotation/transport devices can be rotated through 45° with respect to one another such that the transport direction changes during the transport of the transport containers. As a consequence of the rotation, the transport container can describe a quarter orbit. It is also possible for the transport to be implemented at an angle of 45° with respect to the original direction.